package com.yang.filter;

import com.alibaba.fastjson.JSONObject;
import com.yang.pojo.Result;
import com.yang.utils.JwtUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.StringUtils;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Slf4j
//@WebFilter(urlPatterns = "/*")
public class LoginCheckFilter implements Filter {

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) servletRequest;
        HttpServletResponse resp = (HttpServletResponse) servletResponse;


        //1 获取请求url
        String url = req.getRequestURI().toString();
        log.info("请求的url{}", url);

        //2 判断请求url中是否包含login 如果包含说明是登录操作 放行
        if (url.contains("login")){
            log.info("登录操作放行");
            filterChain.doFilter(servletRequest, servletResponse);
            return;
        }
        //3 获取请求头中的令牌-token
        String jwt = req.getHeader("token");

        //4 判断令牌是否存在 如果不存在 返回错误结果-未登录

        if (!StringUtils.hasLength(jwt)){
            log.info("请求头token为空 返回未登录的信息");
            Result error = Result.error("NOT_LOGIN");
            //手动转换 对象--json ---》 阿里巴巴fastJSON
            String notLogin = JSONObject.toJSONString(error);
            resp.getWriter().write(notLogin);
            return;

        }

        //5 解析token 如果解析失败 返回错误结果-未登录
        try {
            JwtUtils.parseJWT(jwt);
        } catch (Exception e) { //jwt解析失败
            e.printStackTrace();
            log.info("解析令牌失败 返回未登录错误信息");
            Result error = Result.error("NOT_LOGIN");
            //手动转换 对象--json ---》 阿里巴巴fastJSON
            String notLogin = JSONObject.toJSONString(error);
            resp.getWriter().write(notLogin);
            return;
        }


        //6 放行
        log.info("令牌合法 放心");
        filterChain.doFilter(servletRequest,servletResponse);
    }



}
